Oak Insights

August 17 and 18

Late in the summer, it appears our stream dries up. This comes as no surprise, since you can follow the streamcourse to its various sources in about the time it takes to drink a fairly hot cup of coffee. All of those sources lie pretty much within earshot of one another.

When the stream goes dry, we like to walk the streambed upstream from the point where it becomes watered. This year, that encompassed virtually all of the stream within our property, save the grand deep pool at the northern property line. It is a path of discovery, to look at our land edge-on from below grade, and at the revealed secrets of the stream itself.

The steep hillside is a revelation in itself. Though the stream runs tight against it, it is barely eroded—the hillside here is an exposed rockface that both strikes upwards sharply in a smooth plane and forms the flat, rough-hewn streambed. These tiny streams cut downward through the yielding soil until they were deflected by the resistant bedrock.

This summer, the stream rewarded us handsomely for our efforts and interest. Within a few yards of our entry, I spied a bright object floating in a small, still, deep pool sheltered by the undercut bank. A bone or a branch, it appeared at first. On closer examination, I recognized it as a recently-deceased North American river eel, a full fifteen inches long. I say recently deceased because it was intact, complete and without obvious external injuries. It did not appear to have been dropped in transit by a careless predator, but had made it to this literal dead end under its own power—a rather sad end to an astonishing life cycle.

These eels are ubiquitous in streams all the way up the eastern flank of the Blue Ridge, as well as deep into the Shenandoah Valley, at elevations up to 2,500 feet. North American Eels, like all freshwater eels, are catadromous; they live in fresh water, but spawn in the salt waters of the Sargasso Sea. This particular specimen was—by a significant margin—the largest aquatic life form we have seen in this stream. It may also have been one of the first of its kind to come up this streamcourse since the breaching of the Embrey Dam on the Rappahannock at Fredericksburg in 2004.

The deep stream bed and banks are rich with uncountable frogs, easily piqued by our coming, and the small domed bulldozers of box turtles plowing the sandy surface for reasons they keep locked deep within their painted strongboxes.

Continuing upstream, I noted the first of several unusual formation on the exposed streambed. Round mounds of sorted small pebbles, altogether about the diameter of a hubcap and five or six inches high.

Gravel sorts itself in moving water, but not in this fashion. Sorted gravel mounds are made by male River Chubs as a place for the female Chub to lay her eggs, as a place where they can hatch despite the vagaries of stream depths and currents. The male meticulously gathers gravel bit by bit in his mouth, sorting and depositing it in a monumental effort to create a nursery orders of magnitude larger than himself. A short distance updtream, we found a second nest, and possibly a third, less distinct. Each was in the same location relative to the stream, presumably in order to produce the same ideal environment for little chubs.